/Engine/Source/Runtime/Engine/Classes/Engine/StreamableManager.h
Creates a new merged handle which contains this handle as well as any external handles. No delegates are moved, and the new handle is returned for convenience. Parent handles no longer directly trackthis_, but will be correctly linked with the newly merged handle (andthis_ handle is a child of the merged hande).
Either the new merged handle or nullptr when merging isn't feasible
[TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FStreamableHandle](API\Runtime\Engine\Engine\FStreamableHandle) > CreateCombinedHandle ( const TConstArrayView< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FStreamableHandle](API\Runtime\Engine\Engine\FStreamableHandle) >> & OtherHandles )